Automatically-controlled electric heating system



E. L. FONSECA AUTOMATICALLY CONTROLLED ELECTRIC HEATING SYSTEM Filed Jan. 19, 1927 IN TOR flew/1d 1 M @wiww 214M ATTORNEYS Patented May 1, 1928.

UNITED STATES 1,668,199 PATENT OFFICE.

EDWARD I. FONSECA, OF NEWARK, NEW JERSEY, ASSIGNOR TO THE WILCOLATOR COMPANY, OF NEWARK, NEW JERSEY, A

CORPORATION OF DELAWARE.

AUTOMATICALLY-CONTROLLED ELECTRIC HEATING SYSTEM.

Application filed January 19, 1927. Serial No. 162,087.

This invention relates to electrical heating systems which are automatically controlled.

so that a uniform temperature may be maintained, and is concerned more particularly with a system of this type having a plurality of heating elements having a similar energy-consuming capacity and receiving energy from a commonsource of supply. The invention maybe used for numerous purposes, but is of particular utility in connection with the electric heaters used in apparatus for imparting a permanent wave to hair, and that application'of the invention will be described as typical though it is to be understood that the utility of the invention is by no means limited to this use.

Hair waving apparatus. as now commonly constructed, includes a. plurality of heating units of tubular form suspended from a common support. These heating units are metal tubes with a double wall and a heating coil is disposed between the two walls of each tube. In the operation of wavin the hair a large number of curls are first ormed by winding tresses about a rod. These wound curls are then wrapped in a pad which contains moisture, or else wound with strips of fabric which have been dipped in a suitable solution. The wrapped curls are then inserted in the heaters and the latter connected to the source of supply. Ordinarily there are a large number of heaters, as, for example, 36, required for a single waving operation, and all these heaters or a part of them are connected in parallel across the current mains. The heaters are of similar construction and consume equal amounts of energy.

It is desirable in any such system, in order to avoid injury to the hair, that the curls should be exposed to a uniform temperature throughout the Waving operation, and the present invention is accordingly directed to the provision of a heating system of the type specified which includes automatic control mechanism by which the supply of T -cnergy to the heaters may be regulated so that such uniform conditions as to temperature will prevail.

The system includes a plurality of similiar heating devices which draw energy from a common source. All but one of these heaters are used for the waving operation and the excepted heater is employed for use in connecting with the control mechanism. This I which the resistance heating master heater by which the temperature is controlled is arranged tocontain a temperature-responsive element, such as a thermostat. This thermostat is the type which is distorted or otherwise affected as the temperature varies. The thermostatic element is connected with a. suitable switch which controls arelay circuit, in turn controlling the operation of a circuit breaker which makes and breaks the circuit through which current is supplied to all the heaters, including the master heater. This relay circuit is arranged so that when a predetermined low temperature is reached, the main circuit is closed and the heaters are supplied with current. Then the selected low temperature is exceeded,-the circuit breaker is held in closed position by a maintaining circuit, which is established when the circuit breaker is first closed. The heaters then continue in operation, and in the event that the temperature generated by the heaters exceeds a selected value, the temperatureresponsive element causes the maintaining circuit to be' broken and the circuit breaker then opens the supply circuit to the heaters.

In the accompanying drawing there is illustrated conventionally a circuit diagram of the new apparatus, and in this drawing the current supply mains are designated 1 and 2. Across these mains are heaters 3, together with a master heater, generally designated 4. The heaters 3, two of which are shown, although a much larger number are ordinarily connected in the same circuit, are of standard type and are in the form of double-wall tubes, between the walls of coil is placed, encased suitably in' insulation. heater designated 4 may beof a construction similar to the heaters 3, but if desired, may simply consist of a heating coil 5, similar to those employed in the heaters 3.

In one of the lines 1 or 2 there is connected a circuit breaker, generally designated 6. his may be of standard type, and includes contacts 7 and 8, together with a movable member 9 havin a stem 10 which serves as the armature of a solenoid coil 11. The circuit breaker 6 is placed in the connections to the heaters in such a way that when the circuit breaker is closed, as illustrated, the member 9 connects the contacts 7 and 8 and current is supplied to the heaters 3 and the master heater 4:. The circuit breaker is Cal of the spring-opening type and is so arranged that when the solenoid coil 11 is tie-energized, the circuit breaker will open, thus cutting off the supply of energy to the heating elements.

The operation of the circuit breaker is controlled by a switch, generally designated 12, and including a thermostatic strip 13, a portion of which lies within the heating coil 5 and is thus exposed to the temperature gen erated at the master heater. The switch 12 includes a movable contact member 1-1, and three terminals designated 15, 16, and 17, which may be connected in pairs by the switch member 14. The arrangement of the switch is such that as the thermostatic strip 13, which may be of standard bimetallic construction, is warped or distorted by the heat generated at the coil 5, the switch arm 14 is moved to different positions. The switch 12 may also include a setting dial 18, by which the movement of the switch arm 1'1 brought about by the distortion of the strip 13, may be controlled.

Therelay by which the energization of the solenoid coil, and thus the operation of the circuit breaker, is'controlled, includes a line 19 connected to the line 2 at the point 20 at the side of the circuit breaker toward the source of energy. The line 19 leads to a protective resistance 20' and another line 21 leads from this resistance to the contact point 15. From the contact point 16 another line 22 leads to. the point 23, at which point is connected a protective resistance 2-1, connected at its other end by the line 25 to the line 2 on the heater side of the circuit breaker. From the point 23, a line 26 leads to the solenoid coil 11, from which a line 27 leads to the point 28 which is connected by 'a line 29 to the main supply line 1. With this arrangement it will be seen that when the switch arm 14 is placed in its upper position by the action of the thermostatic element, connecting the terminals 15 and 16, current flows from the line 2 through the line 19, resistance 20, line 21, terminal 15, switch-arm 14, terminal 16, line 22, line 26, solenoid coil 11, line 27 point 28, and line 29 to the other supply line 1. The switch arm 14 is placed 1n its upper position connecting terminals 15 and 16 by the thermostatic strip 13 when the latter is exposed to a selected low, temperature. Accordingly, when this temperature is reached, current fiows throughthe solenoid coil, energizing the latter and moving the solenoid to the closed position illustrated. Curr nt now flows through the line 2 and i the circuit breaker to the heaters, including the master heater, and the apparatus is in operation. Upon the closing of the circuit breaker, current may also flow through the circuit breaker to the point 30 in the line 2, beyond the circuit breaker, thence through line 25, resistance at, point 23, line 26, coil 1.' The circuit first described and established by the closing of the contacts 15 and 16 is the closing circuit for the circuit breaker, and as soon as this circuit breaker is closed, the second circuit from the point 30 and through resistance 24: and the solenoid is established and this circuit is a maintaining circuit.

\Vhen the temperature developed bythe flow of energy through the heater 5 exceeds the selected low limit, the thermostatic element 13 becomes distorted and this causes the switch arm 14 to move to an intermediate position, such that contact is broken bet-ween the points 15 and 16, and no contact is made between points 16 and 17. \Vhen the switch arm moves away from the point 15, the. circuit through line 19, resistance 20, line 21, etc.. is broken, andno current.- flows to the solenoidll through this circuit. However, the solenoid is maintained in closed position because of the current received through the circuit breaker thc point 30, line 25, resistance 24, and line 26. Thus the generation of a temperature at the master heater in excess of the predetermined low temperature merely causes the closing circuit of the circuit breaker to be broken, but the circuit breaker, once closed, is maintained in closed position by the maintaining circuit which receives current through the circuit breaker. Accordingly current" continues to flow through the circuit breaker to the heaters until a selected high temperature is reached, at which the switch arm 11 will have been moved down to the position shown by the action of the thermostatic clement.

In thisillustrated position the switch arm 11 connects contacts 16 and 17, in which case it will be observed that current may flow from the point 30, line resistance 24. point 23, line 22, contact 16, contact 17, and line 31 to the point 28. This circuit shunts the solenoid coil and the flow of current through that coil diminishes to the point where it is not sufiicient to maintain the circuit breaker in closed position against the action of the operating spring. Accordingly, the circuit breaker opens and current flow to the heaters is stopped. The heaters remain out of action until the selected low temperature is again' reached, whereupon the circuit first described for closing the circuit breaker is established and the sequence of operations is repeated.

It will be seen that in this system the circuit breaker is controlled by circuits through which fiow currents much less than those flowing through the heaters, this result being noted that there are no connections between fixed and moving points in the heavy duty circuit, such as would ordinarily require the use of heavy pigtails. Such pigtails are undesirable for many reasons, and are likely to become detached from their terminals. Also in this system the maintaining circuit by which the circuit breaker is maintained in closed position, and which is operative when the temperature at the heaters exceeds the selected low temperature, is established through the main circuit breaker contacts. I am aware that it has-been proposed in the past to employ maintaining circuits of this type, but in all of the systems with which I am familiar these maintaining circuits are established through auxiliary contacts, rather than through the main circuit breaker contacts; The use of such auxiliary contacts is undesirable, because, since only a small current is used for maintaining purposes, any dirt on the auxiliary contacts is likely to result in the maintaining circuit being broken and this would cause the deen ergization of the solenoid and the opening of the main line. As a slight rise in temperature developed at the. heaters causes the closing circuit to be opened, it is apparent that the failure of the maintaining circuit to function will result in the opening of the circuit breaker and the cutting off of the flow of currrent to the heaters shortly after such flow has started. The heaters will consequently cool rapidly, the closing circuit will again be established,and the breaker closed and the cycle of operations of the moving parts will be rapidly repeated with resultant wear and no satisfactory heating effect.

With the new device, the heaters which are used at separated points are all of similar construction and-connected to receive the same current, so that by means of the master heater, a single temperature-responsive device may be used to control the temperatures developed at all the heaters. The heating action of all the heaters may thus be carefully regulated and by setting the control switch 12, the temperature to which all the curls are exposed may be controlled within selected limits so that no temperatures are developed which would cause injury to the person being treated.

I claim:

1. An automatically controlled heating system comprising a plurality of similar heaters drawing energy from a common source, a temperature-responsive device exposed to the temperature developed by one of the heaters, a circuit closer for controlling the supply of energy to all the heaters, means for operating the circuit closer to close the circuit through the heaters, the said means being brought into action by the said device when the latter is exposed to a selected low temperature, means brought into action by the circuit closer upon the closing thereof to maintain the circuit closer in closed position, and means controlled by the temperature-responsive device for opening the circuit closer when the said device is exposed to a selected high temperature.

2. An automatically controlled heating system comprising a plurality of similar heaters drawing energy from a common source, a temperature-responsive device exposed to the temperature developed by one of the heaters, a circuit closer for controlling the supply of energy to all the heaters, means for operating the circuit closer to close the said circuit, the said means being brought into action by the said device when the device is exposed to a selected low temperature, a circuit established through the circuit closer when the latter is closed for maintaining the sa-idicircuit closer in closed position, and means controlled by the temperature-responsive device for opening the circuit closer when the said device is exposed to a selected high temperature.

3. An automatically controlled heating system comprising a plurality of similar heaters drawing energy from a common source, a temperature-responsive device ex; posed to the temperature developed by one of the heaters, a circuit closer for controlling the supply of energy to all the heaters, means for operating the circuit closer to close the said. circuit, the said means being brought into action by the said device when the device is exposed to a selected low temperature, a circuit established through the circuitcloser when the latter is closed for maintaining the said circuit closer in closed position, and a circuit under the control of the said temperature-responsive device for causing the circuit closer to open.

4. An automatically controlled heating system comprising a plurality of similar heaters drawing energy from a common source, a temperature-responsive device exposed to the temperature developed by one of the heaters, a circuit closer for controlling the supply of energy to all the heaters, a circuit for operating the circuit closer to close the circuit to the heaters. the said closing circuit being controlled by the temperature-responsive device, means brought into action when the circuit closer is closed for maintaining the circuit closer in the said closed position, and means under the control of the temperature-responsive device for opening the circuit breaker when the said device is exposed to a selected high temperature.

5. An automatically controlled heating system comprising a plurality of similar heaters drawing energy from a. common source, a temperature-responsive device exposed to the temperature developed by one a circuit closer for control of energy to all the heaters,

of the heaters, ling the supply a circuit for closing the circuit closer, a second circuit established through the circuit closer when the latter is in closed position for maintaining the circuitcloser in the said closed position, and a third circuit under the control of the temperature-respons'ive device for causing the circuit closer to open, the third circuit being rendered efiective by the said device when the latter is exposed to a selected high temperature.

6. An automatically controlled heating system comprising a plurality of similar heaters drawing 'energy from a common source, a temperature-responsive device exposed to the temperature developed by one of the heaters, an electrically operated circuit closer for controlling the supply of energy to all the heaters. a circuit for closing the circuit closer, a second circuit established through the circuit closer when the latter is. closed for maintaining the said circuit closer in closed position, and a third circuit for causing the circuit closer to open, the first and third circuits being under the control of the said temperature-responsive device.

7. An automatically controlled heating system comprising a plurality of similar heaters drawing energy from a common source, a temperature-responsive device exposed to the temperature developed by one of the heaters, an electrically operated circuit closer for controlling the supply of energy to all the heaters, a circuit for closing the circuit closer, a switch controlled by the temperature-responsive device for controlling the fiow of current through this closing circuit, a second circuit for maintaining the circuit closer in closed position, established through the circuit closer when the latter is closed, and a third'circuit under the control of the switch for causing the circuit closer to open.

' 8. An automatically controlled heating system comprising a plurality of similar heaters drawing energy from a common source, a temperature-responsive device exposed to the temperature developed by one of the heaters, an electrically operated circuit closer for controlling the supply of en-.

ergy to all the heaters, a circuit in'shunt with the circuit closer for closing the latter,

. a. switch for controlling the flow of current to the said shunt circuit, this switch being controlled by the temperature-responsive device, a second circuit in series with the circuit'closer for maintaining the latter closed, and means controlled by the temperatureresponsive device for causing the circuit closerto open, the latter means being brought into action when the device is exposed to a selected high temperature.

9. An automatically cont-rolled heating system comprising a plurality of similar heaters drawing energy from a common source at the samevolt-age, a temperatureresponsive device exposed to the temperature developed by one of the heaters, a circuit closer for controlling the supply of energy to all the heaters, means controlled by the said device for closing the circuit closer, the said means being brought into action by the said device when the latter is exposed to a selected low temperature, means brought into action by the closing of the circuit closer for maintaining the latter closed, and means under the control of the temperature-responsive 'device for opening the circuit closer, the means last mentioned being brought into action by the said device when the latter is exposed to a selected high temperature.

10. An automatically controlled heating system comprising a pair of supply lines, a plurality of similar heaters connected in parallel across these lines, a temperatureresponsive device exposed to the temperature developed by one of the heaters, a circuit closer for controlling the supply of energy to all the heaters, means for operating the circuit closer to close the circuit to the heaters, the said means being brought into action for causing the circuit closer to open, the said meansbeing brought into action by the said device when the latter is exposed to a selected high temperature.

11. An automatically controlled energy; consuming system comprising a plurality of: similar devices drawing energy from a common source, a control device responsive to variations in the energy consumed by one of the said consuming devices, a circuit closer for controlling the supply of energy to all the said energy consuming devices, means under the control of the said control device for closing the circuit closer, a circuit for maintaining the circuit closer in closed position, established through the circuit closer when the latter is closed, and means under the control of the said control device fol causing the circuit closer to open.

12. An automatically controlled heating system comprising a pair of current supply lines, a plurality of similar heaters connected in parallel across the lines, these heaters producing heating effects wholly independent of one another, and a temperature-responsive device exposed to the temperature developed by a single heater and operable in response to an abnormal temperature de veloped at that heater for cutting off the supply of current to all the heaters.

13. An automatically controlled heating system comprising a source of energy for heating purposes, a plurality of similar trolled by the temperature-responsive device heaters receiving equal amounts of energy from said source, these heaters being wholly independent of one another and producing independent heating effects, and a temperature-responsive device exposed to the temperature developed by a single heater and operable in response to an abnormal temperature at that heater for cutting oil the supply of energy to all the heaters.

14. An automatically controlled heating system comprising a source of energy, a

plurality of similar heaters connected to the source to receive equal amounts of energy, these heaters being independent of one another and producing independent heating effects, a temperature-responsive device exposed to the temperaturedeveloped by a single heater and operable in response to an abnormal temperature at that heater for cutting ofi the supply of energy to all the heaters, and means for adjusting the device to render it operative at selected temperatures.

15. An automatically controlled heating system comprising a source of energy, a plurality of heaters connected to the source to receive equal amounts of energy, these heaters producing heating effects wholly independent of one another, a controlling heating device similar to the heaters and connected to the source to receive the same amount of energy as the heaters, and a temperature-responsive mechanism exposed to the temperature developed by the control heating device and operable in response to an abnormal temperature developed at the said device for cutting off the supply of energy to all the heaters.

In testimony whereof I affix my signature.

EDWARD L. FONSECA. 

